In 2000 I purchased 4 Vifa 3/4" dome supertweeters from Meniscus & made a set of 4 "ambience recovery"(aka surround sound speakers) using those wonderful supertweeters with AC-7 midwoofers.

Years later my primary residence became an antique 28' Airstream style trailer, & in 2007 I decided to make new primary satellite speakers (L, R & C) using those drivers & relegating ambience recovery to small computer speakers. It took lots of tweaking & taming to get those speakers to interface well with my modified solid state electronics, but the end result was stunning. Better than anything I have heard.

In late 2011 I blew both my Left & Right tweeters listening to Mahler's 8th at near concert levels (duh!) & I ordered 2 more from Meniscus dated 2009.(The 4th Vifa tweeter had apparently been chewed on by a rodent after I placed it on the floor overnight.) When I installed those new D19TD-05-08s they proved to be a completely different driver when coupled with my unforgiving detailed solid state power amps. I can describe the new Vifas as forward to the point of being IN YOUR FACE & strident. I won't state what my electronics are because I don't want users advising me to start afresh with new electronics. Padding down those drivers didn't fix the problem as it is a type of intangible that can't be "dialed in" back to where it was.

Someone recommended Vifa soft dome super tweeters & Mark & Chad bent over backwards hunting 3 down for me. The new soft domes were a bit softer than the new plastic domes, but nothing like the aged ones. I sent 2 of them back & just kept one in the right speaker (as thst side of the stage is where trombones, bass & celli are set up.)

No one could verify if the newer D19TD-05-08s were made with a newer plastic formula, but it was obvious the texture of the domes varied markedly. The 2000 dome was like silk, & the 2009 domes were thick, rigid & popped right back when pressed down. I surmised that it was a part of plastic's break down process, as I have observed plastic, synthetic rubber disintegrating with age--particularly when exposed to UV rays. That Summer 2012 I placed the drivers on my car's dash board. Alan Holsabus at Orca design thought it was a good idea. (Of course it's a cheap plastic tweeter, not steel & it warped)

In early 2013 my parrot died (my only real family) & all this as audiophile stuff ceased to be too relevant for some time. I have observed that those newer tweeters are much softer & don't pop back up anymore--but not as soft as the old one. I don't know if playing the driver or sending white noise through it will break it in more.

It would be great to find a used Vifa D19TD-05-08 from the early 2000s in good working condition. eBay vendors can never date their drivers so I hope to find 2 here.